Hydraulic safety clamp.



is a top plein View offinyinventlon; 11

of New-Ytrk, have invent-e tskilld 'in i the am to Lthough itis-not restricjtdfft euch Se "IThey'-al'e"uully inaklefin-sec "on "o been clamped by` "handloperated in With` thee obj ects-'in viewgm" consists" in"the/constructionan y tions" of parte" "asfherente"decribed clain'ied. y i In the accompanyingdifawingS:

a Ion ltudinal section theeofgonth Figi" 3 `iS :tj section` 38 ofFig; l. Figfgis alllongitdi i tml section thronglr thevalveVandl-V chamber. Fig. 5 is asectonvthloiigl valve-'chamber and cylinder-heds' F1gf.\1`6 a View of the valve, detached.

a represente thel bse `offtlie inac y `away centally, 1eaving` :i` space-*gt which the `drill-rod*may panse.;` T is provided With two` hori'zo'rital` a united together bythe" web Cyandont is mounted a cylinder d; which TI'na'y-b `mad integral with the base ori-sepaatetiieref or attached toas desired` Totlielarnis ixed` anabutinent e, Whchcajeson" curved and refezbl 4 L-iil'ghened, in g. This 'Jaw is adjustablyfh dfby of a. set screw k! y in the pin 16, which isadaptedto' l latch when' the 'latteris thrown up intov 3,'untilby further pressure l '8, the pin 16 is disengaged from the latch 15,

- whereupon the s to its normal in Fig. 3.

,"Lin position by means of amsm, as shown 1n F1 projecting from thecylinder head and in these brackets is mounted a rod 13, having a spring 14 and a latch 15 securedthereto. The spring- '14 normally holds the latch 15 position shown in Fig. 3. To the vertical arm of the foot lever 8 is Vattached a mesh with the the position indicated in'ull lines in Fig. 3, which may be done by hand. 'The result is lthat after the .foot lever is pressed down, -.to open the port a of the valve casing, it can b'e locked-in that position, asfshownin Fig.

upon the treadle pring 14 returnsV the latch position, shown in dotted lines The. operation isas follows :-The drill rods, ready for hoisting, .are between the jaws o'fthe clamp." The foot lever8 is held the locking mech- .3, leaving the jaw z' oisted the drill rods disengaged. ,"Having by pressing his foot upon the the operator,

'. Vtreadle 8, releases the latcli-15 from the pin 116, whereu pon the springll lifts the footlever 8, which turn'slthe valve into the posi- 2 the pipe t, passes "the" val-ve, `valve-casing,

' from -the tank tion shown in Fig. 5. Fluid under pressure or pump enters in throu h t rough the opening2in through the passage 'v in the and. strikes the piston n, forcyfing' said piston to the left,'as shown in Fig.

- drill-rod, and hol 2, thereby forcin the jaw a'l toward the fing the latter firmly. At

i the same time the fluid behindv thepiston is -thefpipe u. The

"allowed to escape. It passes out through the passage through the opening spinto a' shallow groove 4, and finally out through parts remain in this osition until a sectionof the drill rods has een Q his foot upon the Y fluid from the -pum removed, whereupon the operator presses treadle 8, bringing the original position. The

then Hows in through e passage which regvalve` back into its the opening 3 into t isters therewith, and its original position,

from the drill-rod. Meantime the fluid which had beenused to force the piston n nary work the operation is repeated as desired without using the locking mechover to clamp the drill-rod is allowed to escape, passing through the passa e fv, the shallow groove 4, and out throug the escape-pipe u intoY the atmosphere. Invordias often anism shown in Fig. 3.

By means of the set screw z and an abut- (not shown) inserted back of the jaw clamp.

While I have thus described my invention, I wish it to be distinctly understood that Il do not limit myself to the exact debase, a fixed returns 'the piston n to disengaging the jaw z" lton in said cylinder,

tails shown and described,as these might be varied widely without departing from the spirit of my invention, the broad idea of which is to use a power clamp for drill-rods and vfor similar purposes, which automatically locks itself when the power is thrown on, and by which as great a pressure as is desired can be maintained upon the drillrod or similar part.

I claim 1. In a safety clamp, the combination of a jaw and a movable jaw mounted on said base, a fluid-operated piston for movingV said movable jaw2 a valve for controlling the sup ly of fluid which operates said piston, an means for holding said valve againstmovement when the movable jaw has been moved to clamp a drill rod, substantially as described.v

2. In a safety clamp, the combination of a base, a fixed jaw, a movable jaw, and a cylinder, mounted on said base, a piston in said cylinder, a piston rod connecting said piston with the movable jaw, a valve casing connected to the cylinder head, a rotatable valve mounted in said casing, means for operating said valve, and means for holdin said valve in one position when the d rod has .been firmly clamped, substantially as described. l 4

3. In a safety clamp, the combination of a base, a fixed jaw, inder, all mounted on said base, a piston in said cylinder, a piston rod connecting said cylinder and the movable jaw, a valve casing connected to said cylinder and provided with inlet and outlet means, said cylinder and valve casing being sages leading,res ective y, to each en 0f the cylinder, a va ve mounted in said valve casing, means for operating said valve, and means for preventing the motion of said valve when the drill rod is clamped, sub-- stantially as described.

4. In a safety clamp, the combination of a base, a jaw normally fixed but adjustably mounted thereon, a movable jaw on said base, a cylinder mounted on said base, a isa piston rod connecting said piston with the movable jaw, a valve casing connectedl to said cylinder, said c linder and valve casing being provided with passages leading to each end of said cylinder, a valve mounted in said valve casing, means for operating said valve, a spring normally holding said valve in an operative position, and means for holding said operating means stationary, in spite of the tension of said spring, substantially as described.

5. In a safety clamp, the combination of a suitable base, a fixed jaw, a movable jaw, and a cylinder, all mounted on said base, a piston in said cylinder, a'piston rod con= necting said piston with the movable jaw, a valve casing secured to said cylinder and a movable jaw, and a cylrovided with asprovided with an inlet pipe and en outlet has been `operated end until released, subpipe, said valve casing and cylinder being stantially als described. 10 provided with passages leading to each end In testimony whereof7 I aiix my signaof said cylinder, a valve rotatably mounted ture, in presence of tWo Witnesses. 5 in the valve casing, e lever for operating MATTHIAS GARVEY.

said valve, aspring normally resisting said Witnesses: operation, and means for holding said lever, t D. P. WALKER,

despite the tension of seid spring, after it W. Gr. COFFEY. 

